Les effets du décrochement de Tizi-n-Test sur l'évolution du bassin d'Ijoukak (Haut Atlas, Maroc) Effects of the Tizi-n-Test strike-slip fault on the evolution of the Ijoukak basin (High Atlas, Morocco)

International audienceL'analyse sédimentologique des dépôts triasiques du bassin d'Ijoukak (haute vallée de N'Fis) et leur comparaison avec d'autres séries du Haut Atlas, notamment celles de Talaat-n-Yacoub et d'Idni, celles de l'Ourika et celle d'Aït Tamlil, ont permis la corrélation des différentes formations par analogie de faciès. L'étude tectonique de ce bassin a mis en évidence le rôle joué par l'accident majeur de Tizi-n-Test dans le contrôle de la sédimentation triasique et la structuration atlasique du bassin d'Ijoukak. Sedimentological analysis of Triassic deposits of the Ijoukak basin (High valley of N'Fis) and their comparison with other series in the High Atlas, notably the Talaat-n-Yacoub series, the Ourika and the Aït Tamlil ones, allowed us a correlation of different formations by facies analogy. Structural study of this basin shows the role of the Tizi-n-Test strike-slip fault in the control of the triassic sedimenta-tion and in the atlasic structuring of the Ijoukak basin

Impact of Anthropogenic Facilities on the Morphodynamic Evolution of an Estuarine System: The Case of Oum Er-Rbia Estuary (Azemmour, Morocco)

The Oum Er-Rbia estuary is located on the Atlantic littoral of Morocco. It undergoes severe clogging due to the sand deposition in its outlet. The current study examined the indicators of the morphodynamic evolution in the littoral system including the Oum Er-Rbia estuary and the neighboring beaches over 1970–2017. The methodology adopted was based on the analysis and the interpretation of aerial photographs and Google Earth images under a GIS environment and field work. The morphodynamic evolution was discussed by taking into account the evolution of hydraulic facilities installed in the watershed area, especially the construction of dams, as well as the dredging works in the Oum Er-Rbia estuary. The results highlight the morphologic evolution estimated in terms of surface units observed in the estuary and the neighboring beaches. The evolution of the littoral system was mainly influenced by the closest dam location and by the dredging works, in addition to the regulation of the river flow by the installation of hydraulic facilities upstream